1. Field of the Invention
The present invention relates to the robot apparatus which moves on a floor and, more particularly, to the robot apparatus, a method for turning the robot apparatus, and a computer program product which can cause the robot to turn a commanded angle correctly by compensating for a skid on the floor.
2. Description of the Related Art
Moving methods for moving a robot apparatus are roughly categorized into two categories.
One robot apparatus moves along a route set exterior to the robot apparatus by a rail on which the robot travels, and another robot apparatus moves unconstrained by an exterior structure and moves autonomously based on a programmed moving function controlling movement of legs or wheels of the robot.
Since the former has a fixed route, a movement to a target point is correctly and easily controllable, and such a robot apparatus is suitable for repetitive jobs in a predetermined location, such as line jobs at a plant etc.
Autonomous robots are more flexible, but cannot necessarily be correctly guided to a target position of an object. For example, there is known a method of driving a robot apparatus so that it may reach an exact location of an object by carrying an arm in the robot apparatus, attaching a camera to the arm, taking in an image of the object beforehand at the target position of the robot apparatus as a reference image, comparing the reference image with a present image of objects and based on a direction and a location of the camera, controlling movement of the robot so that the present image may be in agreement with the reference image, as disclosed in for example, Japanese patent application (Kokai) No. 2003-305676.
On the other hand, since the latter involves external factors, such as friction and a skid in tread with a floor, even if robot movement is exactly controlled, errors, such as in the form of a gap actually arise.
Therefore, if controls are performed only, for example by external sensors, such as sensors which remove a rotation amount of the wheel, a commanded movement will be different than actual movement.
Especially, by an advance direction shifting only somewhat at the time of changing the advance direction of the robot apparatus, if it moves after that, a large gap will arise in location.